Slider-type assembly device

ABSTRACT

An assembly device comprising two identical forkshaped strips each having two arms and formed of elastically deformable materiel and a slider for opening and closing said device. The first arm is in the form of a tongue and the second arm has at least one terminal bead and one recess for receiving the terminal bead of the other strip. The second arm of each strip is clamped between the tongue and the second arm of the other strip in the interlocking position.

United States Patent [1 1 Gilles et a1. 1

SLlDElR-TYPE ASSEMBLY DEVICE Inventors: Roger Gilles, Lons, Pau; Francis Nougarede, La Celle-Saint-Cloud, both of France Entreprise De Recherches Et DActivites Petrolieres (ELF), Paris, France Filed: May 25, 1971 Appl. No.: 146,722

Assignee:

Foreign Application Priority Data May 28, 1970 France 7019505 US. Cl 24/201 C Int. Cl A44b 19/ 10 Field of Search 26/201 C References Cited UNITED STATES PATENTS 11/1953 Koutnik 24/201 C [451 Feb. 12, 1974 3,159,889 12/1964 Brandl 24/201 C FOREIGN PATENTS OR APPLICATIONS 1,034,230 7/1953 France 24/201 C 218,982 1/1962 Austria 24/201 C 1,197,270 7/1970 Great Britain 24/201 C 469,879 3/1952 Italy 24/201 C 507,223 12/1954 Italy 24/201 C 521,051 3/1955 Italy 24/201 C Primary ExaminerBemard A. Gelak 5 7 ABSTRACT An assembly device comprising two identical forkshaped strips each having two arms and formed of elastically deformable materiel and a slider for opening and closing said device. The first arm is in the form of a tongue and the second arm has at least one terminal bead and one recess for receiving the terminal bead of the other strip. The second arm of each strip is clamped between the tongue and the second arm of the other strip in the interlocking position.

6 Claims, 5 Drawing Figures Patented Feb. 12, 1974 3,790,993

2 Sheets-Sheet 1 INVENTORS ROGER GILLES 8: FRANCIS NOUGAREDE ATTORNEYS Patented Feb. 12, 1974 3,790,993

2 Shae ts-Shoe t 2 IN VENTORS ROGER GILLES 8a FRANCIS NOUGAREDE ATTORNEYS SLIDER-TYPE ASSEMBLY DEVICE- This invention relates to an assembly device of the type which is commonly referred-to as a slide fastener and which comprises two strips of elastically deformable material and a closing and opening slider which serves to interlock the strips as a result of engagement of beads formed on the strips when said slider is displaced in one direction and to separate said strips when these latter are displaced along the device in the opposite direction.

Many different styles of slide fasteners are at present in existence but are subject to a disadvantage in that they fail to provide leak-tight closure between the two strips. This drawback is apparent-in the case of assembly devices which make use of hooks and is also present in bead-type devices; in this case a fluid located on one side of the device tends to seep between the beads, with the result that the cooperating portions of the two strips are slightly separated if the device is subjected even to low pressure.

The primary object of the invention is to provide an assembly device which meets practical requirements more effectively than comparable devices which were proposed in the prior art, particularly insofar as said device ensures a leak-tight connection between the two faces of this latter.

To this end, the invention proposes an assembly device of the type referred-to as a slide fastener comprising two identical fork-shaped strips each having two arms and formed of elastically deformable material and a slider for opening and closing said device. The device is distinguished by the fact that the first arm is in the form of a tongue and that the second arm has at least one terminal bead and one recess for receiving the terminal bead of the other strip, the second arm of each strip being clamped between the tongue and the second arm of the other strip in the interlocking position.

Leak-tightness of the above-mentioned device is essentially ensured by the presence of the tongues if a suitable shape in the state of rest is given to each strip, the tongues are applied elastically against the second arms. In the case of the tongue which is located on the side corresponding to the highest pressure, this elastic force is added to the autoclave action which is exerted on the outer face of the tongue.

The assembly devices of the prior art have the further disadvantage of opening by separation of the strips if these latter are subjected to tractive forces in opposite directions which tend to move said strips away from each other. The invention proposes an assembly device constituting a particular embodiment which is not attended by the above-mentioned disadvantage. In this device, the second arm of each strip is provided in addition to the terminal bead withan inner bead which is similar in shape to said terminal bead. A first recess which is formed by the two heads of each strip is intended to accommodate the inner bead of the other strip. A second recess is formed by the bottom portion of each strip and its inner bead is intended to accommodate the terminal bead of the other strip.

If tractive forces are applied to the strips and tend to separate these latter, the combined action of the beads and of the sealing lips strengthens the fastening so that the resistance to opening of the assembly device is limited in practice only by the tearing strength.

It is readily apparent that provision can be made for 7 more than two beads although this arrangement does not usually present any additional advantage and complicates the slider. r

A better understanding of the invention will be obtained from the following description of assembly devices which constitute practical applications of the invention and are given by way of example without any limitation being implied, reference being made to the accompanying drawings, wherein:

FIG. 1 shows an assembly device which makes use of strips having only a single bead as shown in crosssection along a plane at right angles to the direction of displacement of the slider;

FIG. 2 which is similar to FIG. 1 shows an assembly device in which the strips are made up of two beads;

FIGS. 3 and 4 which are similar to FIG. 2 illustrate the progressive engagement of the strips at the time of closure of the assemly which is shown in FIG. 2;

FIG. 5 shows very diagrammatically one mode of fabrication of strips by simultaneous extrusion of two strips of the same device.

The fastening device which is illustrated in FIG. 1 is intended to join two edges 10 which are placed in the same plane. Said edges 10 can form part of a single sheet so that, after fastening by means of the assembly device, the strip forms a substantially leak-tight duct. Noteworthy applications in which the ducts thus formed can be incorporated include the heat insulation of pipelines: the strip is closed over the pipeline which is fitted with spacer members and constitutes a sheath into which an expanded heat-insulating product can be injected.

The assembly device is made up of two strips 12 and 12' and a slider 14. The strips are identical and are located relatively to each other in a position which is symmetrical with respect to the axis of the device and to the direction of displacement of the slider. Each strip has a fork-shaped cross-section with two prongs or arms. The first arm is formed by a tonue 14 or 14'. The second arm has a length which is substantially equal to that of the first when the strip is free and has a terminal bead 16 or 16' which forms a recess with the bottom I portion 18 or 18' of the fork, said recess being intended to accommodate the terminal bead of the other strip.

Each strip is formed of elastically deformable material and has a shape in the rest position such that, when the two strips are assembled together, the tongue 14 or 14' of each strip is applied elastically against the second arm of the other strip 12' or 12. It is possible in particular to employ strips which are fabricated from plastic material such as polyethylene or polyvinyl.

It is evident that the strip can have very rounded shapes in order to prevent notching effects and the possibility of tearing. This is particularly true in the case of cooperating bulges and recesses.

In the preferred embodiment which is illustrated in FIG. 2, the interassembled beaded edges intersect the mid-plane of the device at an angle a of the order of 45 this value can be considered as a satisfactory compromise between ease of engagement and strength of interlocking.

In the embodiment which is illustrated in FIG. 1, the strips are provided with heels 20 and 20' over which the slider 22 is capable of displacement. The thickness of each heel is greater than that of the strip-attachment borders 24 and 24' and the design function of said heels is to protect the edges and 10' against the action of the slider.

As has been mentioned earlier, the assembly device which has just been described can be employed for the purpose of joining two edges 10 and 10 of a sheet and thus of forming a duct. The strip can in that case be fabricated from plastic material such as polyethylene or polyvinyl either in the simple form or reinforced with fibers. In this case, seam-bonding of the strips can be carried out very easily.

If the same plastic material as the sheet is employed in order to form the strips 12 and 12, the dimensions of the fastening beads will be greater than the thickness of the sheet by reason of the fact that, in respect of a given tractive force, the resistance to the tensile stresses which are developed in the sheet is greater than the resistance to the shearing stresses which arise in the beads.

The slider 22 and the fastening sequence will not be described in this case since they are similar to those of the assembly device of FIGS. 2 to 4 while being clearly more simple.

The form of construction which is illustrated in FIG. 2 differs essentially from the previous embodiment in that each strip is provided with two beads, the slider being evidently modified accordingly. For the sake of enhanced clarity, the corresponding components of FIGS. 1 and 2 are designated by the same reference numerals which are followed in FIG. 2 by the index a.

The strips 12a and l2'a of FIG. 2 are identical. The strip 12a is further provided with a first arm constituted by a tongue 14a and a second arm. Said second arm is provided not only with a terminal bead 16a but also with an inner bead 26a having a shape which is practically identical with that of the bead 16a and forming in conjunction with the bottom portion 18a a recess which is intended to accommodate the terminal bulge l6a. The inner bead 26a also delimits, in this case in conjunction with the terminal bead 16a, a recess which is intended to receive the inner bead 26a of the strip l2'a.

The assembly device of FIG. 2 has an advantage over that of FIG. 1 in that it has a self-locking action when the strips are subjected to forces which tend to separate the latter. When tangential tractive forces are applied to the strips, each inner bead is accordingly clamped between the inner bead and the terminal bead of the other strip (said terminal bead being in turn imprisoned by the lip). The lip of each strip prevents the terminal bead which forms part of the other strip from being suddenly released from its recess. The action just mentioned can be increased by providing the lips with a shape in the state of rest such that these latter are applied elastically against the other arms when the assembly device is closed; this action is in any case enhanced when a pressure difference is exerted between the two faces of the fastening since the pressure forces tend to apply the lip of one strip even more firmly against the second arm which forms part of the other strip.

The strips can be fabricated by a number of different methods and especially by extrusion. When the device is intended to join the edges of a sheet in order to form a duct, it can prove advantageous to extrude the sheet and the two strips simultaneously. This avoids the need for subsequent bonding in addition to the fact that the presence of the heel is no longer necessary. single annular component is thus formed (as shown in FIG. 5) and is cut in the plane 36.

Whether the sheet which is intended to form a duct is manufactured by the method referred-to above or by bonding the strips to the edges of a sheet, the operation can be rendered highly automatic. The resulting product can be provided in a very substantial length and wound on a drum for delivery and easy use on site.

The strips are presented opposite to each other and interengaged at the time of fastening by means of the slider 22a. Said slider is of the volute type (that is to say is designed in much the same manner as the hemstitching attachments of sewing machines) and opensout the arms of each strip, inserts the beads successively into the corresponding recesses and permits the arms to close again elastically. These operations must be carried out without any excessive bending stress, thereby imposing conditions on the transverse crosssections both of the strips and of the slider and on the lengthwise profile of said slider. It is possible in particular to adopt a slider which is provided successively from the front to the rear (in the direction of displacement of the slider at the time of closure) with the transverse cross-sections which are illustrated in FIGS. 3, 4 and 2. The minimum length of the slider is governed by the flexibility of the material which constitutes the strips.

The slider which is illustrated can be formed either of metal or of molded plastic material either in one piece or preferably in a number of assembled pieces having due regard to the complex shape of said slider.

Looking in plan on the slider 22a, this latter has a convergent shape from the front towards the rear (namely in the direction of displacement at the time of closure). The edges of the slider bear on the heels of the strips and exert on these latter at the time of closure an action which tends to bring said strips together from a relative position (not shown) in which they are separated to a fully engaged position (as shown in FIG. 2). At the same time, passageways which are formed in the slider serve to guide the arms. As shown in FIG. 3, provision is made for two fingers 28 and 34. The finger 28 separates a duct 30 which serves to guide the second arm of the strip from a duct 32 which serves to guide the lip 14a of the strip l2'a. The finger 34 partially delimits a duct 36 for guiding the lip 14a and serves as a support for the second arm of the strip l2'a.

Engagement is carried out as follows when the slider moves forward, the passageways 30 and 36 serve to open-out the two arms of the strip 12. The action of the slider on the heel of the strip l2a causes the strip to rotate, thrusts its second arm into the bottom portion of the strip 12a and bends said second arm so that the mean fiber of this latter assumes the shape which is indicated in dashed lines in FIG. 3. The lip 14'a which is retained by the passageway 32 does not hinder the insertion of the second arm of the strip l2'a. The bead 26a is then caused to engage progressively in the recess which is intended to receive it and which opens-out by bending the second arm of the strip l2'a. The bead 26a thus engages in the direction of the arrows f of FIG. 3. At this level, the strips assume the shape indicated in FIG. 4. The fingers 28 and 34 progressively withdraw; at the same time, the only remaining wall of the passageway 30 forces back the terminal bead 16a to its final position while the passageway allows the lip 14a to return elastically and to bear on the second arm of the strip l2'a. Finally the cross-sectional shape of the slider progressively changes to the shape which is shown in FIG. 2. At this stage, the interlocking process is completed.

What we claim is:

l. A fastening device, comprising two generally symmetrical fork-shaped strips formed of an elastically deformable material, sliding means cooperating with said strips for coupling and uncoupling said strips, each strip including a base portion, first and second arms of substantially the same length projecting from said base portion, each of said first arms being in the form of a generally flat tongue, each of said second arms including a bead projecting from the outer end thereof toward said first arm and forming a recess between said bead and said base portion, the lateral dimension of said bead being greater in the portion closer to said first arm than the portion connected to said second arm so that when said strips are coupled together, the portions of said beads in engagement intersect the longitudinal midplane of said device at an angle less than 90, said recess being shaped and dimensioned to receive and accomodate the bead of the other strip when said strips are coupled together.

2. The fastening device in claim 1, wherein the portions of said beads in engagement intersect the longitudinal midplane of said device at an angle of about 45.

3. A fastening device comprising two generally symmetrical fork-shaped strips formed of an elastically deformable material, sliding means cooperating with the said strips for coupling and uncoupling said strips, each strip including a base portion, first and second arms of substantially the same length projecting from said base portion, each of said first arms being in the form of a generally flat tongue, each of said second arms including a terminal bead at the end thereof and an intermediate bead, both beads projecting toward said first arm, aid beads forming a first recess therebetween and a second recess between said intermediate bead and said base portion, the lateral dimension of said beads being greater in the portion closer to said first arm than the portion connected to said second arm so that when said strips are coupled together the portions of said beads in engagement intersect the longitudinal midplane of said device at an angle less than 90, said first and second recesses being shaped and dimensioned to receive and accomodate said intermediate and terminal beads, respectively, of the other strip when said strips are coupled together.

4. The fastening device in claim 3, wherein the portions of said beads in engagement intersect the longitudinal midplane of said device at an angle of about 45 5. Afastening device comprising, two generally symmetrical fork-shaped strips formed of an elastically deformable material, sliding means cooperating with the said strips for coupling and uncoupling said strips, each strip including a base portion, first and second arms of substantially the same length projecting from said base portion, each of said first arms being in the form of a generally flat tongue, each of said second arms including a terminal bead at the end thereof and an intermediate bead, both beads projecting toward said first arm, said beads forming a first recess therebetween and a second recess between said intermediate bead and said base portion, said first and second recesses being shaped and dimensioned to receive said intermediate and terminal beads, respectively, of the other strip when said strips are coupled together, said sliding means including a pair of surfaces facing each other capable of coupling and uncoupling said strips by moving back and forth along said strips, said strips extending between said surfaces, at least a portion of each surface gradually changing shape in the direction of said back i and forth movement, a finger gradually changing in size projecting from said portion of each of said surfaces and extending along the direction of said back and forth movement, the surfaces and fingers being shaped to contact the strips and urge them toward each other, while the surfaces are moved in one direction, by separating the arms of each strip a sufficient amount so that the second arm of the first strip can be inserted to the limit of travel between the arms of the second strip, the base portion of the second strip being maintained substantially along the plane of symmetry of the strips when coupled while the base of the first strip is disposed at an angle relative to said plane, said surfaces and fingers operating to couple the strips together after the second arm of the first strip has been inserted to its limit of travel by returning the second arm of the second strip to its relaxed position and rotating the first strip toward the plane of symmetry.

6. The fastening device in claim 5, wherein the base of each strip is disposed substantially along the plane of symmetry before the strips are contacted by the surfaces, the surfaces rotating the first strip away from the plane while the arms of each strip are being separated and the strips are being urged toward each other. 

1. A fastening device, comprising two generally symmetrical fork-shaped strips formed of an elastically deformable material, sliding means cooperating with said strips for coupling and uncoupling said strips, each strip including a base portion, first and second arms of substantially the same length projecting from said base portion, each of said first arms being in the form of a generally flat tongue, each of said second arms including a bead projecting from the outer end thereof toward said first arm and forming a recess between said bead and said base portion, the lateral dimension of said bead being greater in the portion closer to said first arm than the portion connected to said second arm so that when said strips are coupled together, the portions of said beads in engagement intersect the longitudinal midplane of said device at an angle less than 90*, said recess being shaped and dimensioned to receive and accomodate the bead of the other strip when said strips are coupled together.
 2. The fastening device in claim 1, wherein the portions of said beads in engagement intersect the longitudinal midplane of said device at an angle of about 45*.
 3. A fastening device comprising two generally symmetrical fork-shaped strips formed of an elastically deformable material, sliding means cooperating with the said strips for coupling and uncoupling said strips, each strip including a base portion, first and second arms of substantially the same length projecting from said base portion, each of said first arms being in the form of a generally flat tongue, each of said second arms including a terminal bead at the end thereof and an intermediate bead, both beads projecting toward said first arm, aid beads forming a first recess therebetween and a second recess between said intermediate bead and said base portion, the lateral dimension of said beads being greater in the portion closer to said first arm than the portion connected to said second arm so that when said strips are coupled together the portions of said beads in engagement intersect the longitudinal midplane of said device at an angle less than 90*, said first and second recesses being shaped and dimensioned to receive and accomodate said intermediate and terminal beads, respectively, of the other strip when said strips are coupled together.
 4. The fastening device in claim 3, wherein the portions of said beads in engagement intersect the longitudinal midplane of said device at an angle of about 45*.
 5. A fastening device comprising, two generally symmetrical fork-shaped strips formed of an elastically deformable material, sliding means cooperating with the said strips for coupling and uncoupling said strips, each strip including a base portion, first and second arms of substantially the same length projecting from said base portion, each of said first arms being in the form of a generally flat tongue, each of said second arms including a terminal bead at the end thereof and an intermediate bead, both beads projecting toward said first arm, said beads forming a first recess therebetween and a second recess between said intermediate bead and said base portion, said first and second recesses being shaped and dimensioned to receive said intermediate and terminal beads, respectively, of the other strip when said strips are coupled together, said sliding means including a pair of surfaces facing each other capable of coupling and uncoupling said strips by moving back and forth along said strips, said strips extending between said surfaces, at least a portion of each surface gradually changing shape in the direction of said back and forth movement, a finger gradually changing in size projecting from said portion of each of said surfaces and extending along the direction of said back and forth movement, the surfaces and fingers being shaped to contact the strips and urge them toward each other, while the surfaces are moved in one direction, by separating the arms of each strip a sufficient amount so that the second arm of the first strip can be inserted to the limit of travel between the arms of the second strip, the base portion of the second strip being maintained substantially along the plane of symmetry of the strips when coupled while the base of the first strip is disposed at an angle relative to said plane, said surfaces and fingers operating to couple the strips together after the second arm of the first strip has been inserted to its limit of travel by returning the second arm of the second strip to its relaxed position and rotating the first strip toward the plane of symmetry.
 6. The fastening device in claim 5, wherein the base of each strip is disposed substantially along the plane of symmetry before the strips are contacted by the surfaces, the surfaces rotating the first strip away from the plane while the arms of each strip are being separated and the strips are being urged toward each other. 